Conventionally, there are known pachinko-type gaming machines comprising slot machine and reel units that carry out re-drawing. For example, in the pachinko gaming machine disclosed in Publication of Japanese Patent No. 3330338, when a player operates a hitting handle, pachinko balls are hit into a game region formed in a front surface of a game board one by one. A reel unit that can change display or stop display of a plurality of symbols, and a plurality of starting winning holes are provided on the play surface. In a case where a pachinko ball goes into any of the starting winning holes, the pachinko ball is detected by a starting winning ball detector, and each reel in the reel unit rotates based on a detection signal of the starting winning ball detector, so as to change display the plurality of symbols. After a predetermined time has passed, a second reel (center reel) stops, and in a case where the second reel that stops is a symbol other than a specific symbol, a first reel (left reel) stops thereafter, and finally, a third reel (right reel) stops. When every reel stops, in a case where a combination of pre-set specific symbols are displayed, a situation favorable for the player occurs by for example, opening an opening/closing plate of a variable prize winning ball device in a tulip-shape, and creating a situation where a predetermined game value can be provided to the player.
Each reel can display three symbols in the longitudinal direction. Therefore, symbols displayed by the three reels are in a 3×3 matrix alignment. In this matrix, a total of five lines are formed: three horizontal lines and two diagonal lines.
On the other hand, in a case where a symbol stop displayed is a specified symbol (for example “7”) at the time the second reel stops, the change display discussed below is carried out. The first and third reels continue change display of the symbols, but the first and third reels are stopped at the same time, or are stopped in an order of first reel, then the third reel, after slowly rotating the “7” symbol horizontally, downwards, or upwards, in a state where the symbols are matched. By this, a situation where a matching is possible in a win line of a center horizontal direction, a win line of a downward direction, or win line of an upwards direction is possible, while the rotation of the first and third reels.
However, in the conventional re-drawing method, it is difficult to correspond to a slot machine with many reels, or a slot machine that validates a plurality of symbols on one reel. In the conventional method, when a predetermined condition is met, re-drawing is carried out by the entire reels, so as to standardize variation of re-drawing. Because this kind of method is well known, it is becoming insufficient to arouse player interest. Accordingly, there is a need for a new method that increases variation, and the possibility of finding new game functions in order to increase player interest towards the game.
Gaming machines such as slot machines, poker machines, fruit machines, and the like generally attract enormous popularity from players in casinos. Such a gaming machine displays an arrangement of symbols on the front thereof, and randomly changes types of symbols in the arrangement at each round of game. A player places a bet at the start of each round. If a winning combination appears in the arrangement, the player will win an amount of a payout that depends on the amount of the bet and the type of the winning combination.
This type of gaming machine is generally equipped with mechanical reels that are coaxially arranged and allowed to independently spin by respective motors. Symbols are permanently displayed, e.g., printed on the circumferential surfaces on each reel in a predetermined order. Mechanical reels repeat spins and stops, and thereby change visible symbols at random. Alternatively, this type of gaming machine may use an electric display device to display symbols in graphic form on a screen thereof. The symbols are aligned in two or more columns, i.e., video reels. Like mechanical reels repeating spins and stops, video reels repeatedly change in appearance, and thereby symbols repeatedly move and stop in a vertical direction. Such actions of symbols are often referred to as “spins and stops of video reels”. There is also a mechanical reel with one or more electric display devices mounted on the circumferential surface of the mechanical reel. Symbols are displayed in graphic form on a screen of the electric display device. Visible symbols move and change, whichever the mechanical reel spins or the electric display device changes images produced thereon.
Most players prefer a gaming machine that can provide a larger amount of payout. The upper limit of payout per round generally depends on a total number of types of symbol arrangements visible on reels. Mechanical reels have a limited number of symbol types mainly because of their sizes. In order to increase the upper limit of payout per round, a gaming machine with mechanical reels randomly provides a player with a right to play a bonus round. A player can win a larger amount of payout, or an amount of payout more frequently at a bonus round than at a normal round. In addition, a player can play a bonus round for free.
On the other hand, video reels have no limited number of symbol types in principle. However, a gaming machine with video reels also provides a player with a right to play a bonus round in order to enhance the variety of game contents and visual effects, and thereby attract a larger number of players.
Recent remarkable progress on game controllers, computer graphics, and display devices enables gaming machines to produce more various types of bonus rounds with more complex rules and visual effects. This facilitates differentiation of a type of gaming machines from others. On the other hand, excessively complex rules and visual effects may prevent gaming machines to raise players' expectations for winning In addition, excessively complex rules and visual effects may place a heavy burden on game designers and developers.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved gaming machine that can produce a bonus round with more simple rules and visual effects, and thereby cause a player to recognize the bonus round more clearly and reduce a burden on game designers and developers. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.